You're not the only one ... from what i have gathered it is hapening to lots of people running any of the last few releases of VCC.
On my main rig i am running 12.3 and all is good...
On my gaming rig i have tested 12.10 and 12.11 beta and having flickering issues.
Its not hardware related because my rigs share the same hardware. Something is broken in VCC ....
Pics of my rig
i7 4770k, custom water cooling, 8Gig Corsair Dom 2133 9-11-10-27, ASrock Z87 OC Formula, SilverStone ST-1500 PSU, Creative X-Fi Platinum, Logitech Z-5500D , 2xHIS 7970 CF, Asus VW246H Monitor, Win 7 64Bit HP, Corsair 800D Case